Railway-traffic-controlling apparatus



March. 9 1926. 1,575,783

: B. E. OHAGAN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed oct. 14,.1924

m `J Y {ql/ :o @EN @gag- N 'S nigh 's Nr Y Y%\\ vg .hg

QJ/NX. el

B1 INVENTOR:

l Q .#01- A BY @5&- 'zZ/WMZ ATTORNEY Patented Mar, 9, 1926.

. isilaisa f narran stares PATENT ori-leef BERNARD E. OHAGAN, F SIVISSVALE, PENNSYLVANIA, ASSIGNOR T0 THE UNIN' SWITCH @c SIGNAL COMPANY, 03? PENNSYLVNIA. .I

OF SW'ISSVALE, PENNSYLVANIA, A CORPORATION RAILWAY-TRAFFIC-CON'IROLLING APPARATUS.

Application led October 14, 19724. Serial No. 743,524.

f To all whom t may concern:

Be it known that I, BERNARD E. OI-IA- GAN, a citizen of the United States, residing at Swissvale, in the county of Alle- 5 gheny and State of Pennsylvania, have invented certain new and useful Improvements in Railway-Traffic-Controlling Apparatus, of which the following is a specio of in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention.

Referring to the drawing, the reference characters l and 1a designate the track rails of a stretch of railway track. These track rails are divided, by' means of insulated joints 2, into a plurality of successive track sections, of which only one complete track section A+B is shown inthe drawing. l

Each track section is provided with a track transformer designated by the reference character T with an exponent corre' spending to the location and having a secondary'wi'nding 5 connected across the rails adjacent the right hand end of the corresponding section. An impedance 6 is interposed between secondary 5 of cach track transformer T and one rail, l, of the associated section in the usual manner. The primary 411 of each track transformer is constantly supplied with alternating current from some suitable source such as an alternator M, over line wires 3 and 3.

Each section is also provided with a track relay designated by the reference character It with a suitable exponent, which relay is connected across the rails adjacent the entrance end of the associated section. These track relays may be used to control traffic governing apparatus not shown in the drawing in any desired manner.

Means are also provided for supplying section ,Af-B with train controlling loop will then point out the novel features there-- current which, inthe present disclosure, flows through the two rails ofthe section in parallel.k For this purpose I connect ytwo cent the left hand and right hand ends respectively, ofthe section. The immediate .source of this loop current is a loop transformer L having a secondary winding 8 the terminals of which are constantly connected with the mid points of impedances lO and 13, respectively. The primary 7 of transformer L is supplied with alternating current from line wires 3 and 3 over a front contact 9 of track relay RB. It is therefore plain that when relay RB is energized, alternating loop current is supplied to the rails of section AB throughout vtheir' length from transformer L.

strictive indication is received on the train but when this supply is discontinued, a more restrictive indication is received on the train. In at least one form of apparatus arrangedk to co-operate in this manner the loop current in the track rails controls the train car'ied mechanism through the medium of a receiving device carried on the train in inductive ,relation with the track rails l Under some conditions, as when the track sections are very long or the ballast resistance is very low, a portion of the loop current leaks away from the rails at or near one end of the section, traverses Vthe ground instead of the track rails, and returns to the rails at or near the other end of thessection. As a result the magnitude of the loop current is less near the center than at the ends of the section. In some cases this condition may become soexaggerated as to render the operation -of the train carried mechanism unreliable because the energy transferred to this mechanism by the receiving devices is not suiicient to operate the mechanism when the train is in the middle of the section.

In order to overcome thisv undesirable condition I provide two impedances 11 and 12 similar to impedances 10 andjl and connected across the rails at spacedpoints beyimpedances 10 and 13 across the rails adjaf tween impedances 10 4and 13. 4I also provide an auxiliary loop transformer L2 having a primary winding` 7 connected in parallel with ther prinnuy winding,l T of transformer L and 'having the terminals of its secondary 8 constantly connected with the mid points of impedances 11 and 12, respectively.

It follows that when transformer L is supplying loop current tothe rails of the section between iinpedances 10 and 13, transformer L2 also supplies loop current to the rails between iinpedances 11 and 12. The points of connection ofimpedances'll and 12 and the magnitude of the current delivered by transformer L2 are so chosen that when relay RB is energized the total loop 'current at any point in the section is always of sufficient magnitude to insure reliable operation of the train carried mechanism;

Although I have herein shown and described only one form of trackwayapparatus embodying my invention, it is under'- stood that various changes and modilications may be made therein within the scope of the appended claims without departing` from the spirit and scope of my invention.

l-Iavingthus described my invention, what I claim is:

1. In combination, a stretch of railway track, and means for simultaneously supplying` train controllingl loop current to the two rails of said stretch in parallel vthroughout the saine portion of thef stretch from two sources.

2. In combination, a stretch of railway track,- means for supplying train controlline` energy to the twov rails in parallel lietween two points in the stretch, and other means for simultaneously supplying train controlling` energy tothe two rails in lparallel between two points at least one of which is between said two I'irst mentioned points.

In combination, a stretch of railway track, means for supplying train controlling energy to the two rails in parallel between two points in the stretch, and other means for simultaneously supplying train controllintv energy to the two rails ni parallel be tween two points both ot which last mentioned points are between said two first mentioned points.

1l. In combination, a stretch of railway track, a train controlling' circuit for said stretch including' the rails in parallel lietween two spaced vpoints and the secondary of a first transformer, a second train controlling circuit for said stretch including' the secondary of a second transformer andthe rails in parallel between two other points both of which yare located between said two 'first mentioned points, and means for simultaneously supplying` energy to the primaries of said first and said second transformers.

In combination, la stretch of railway track, a first pair of impedances connected across the rails at spaced points in the stretch, a second pair of impedances connected across the rails yat spaced points between said .tirst pair of iinpedances, a source of energy connected with the mid points ot said first pair of -impedances, and a second source of energy connected with the mid points of said secondpair'of in'ipedances.

(i. In combination, a stretch of railway track, a first pair of impedances connected across the rails at spaced points in the stretch, a` second pair of impedances connected across the rails at spaced points bctween said first pair of impedances, a transformer having a secondary winding connectved with the mid points of said rst pair of impedances, a second transformer having a secondary windingconnected with the mid points of the secondsaid pair ot' im pedances` and means for at times simultaneously suplplying' energy to the primary of both said transformers. f

In testimony whereof I affix my signature.

BERNARD E. OHAGAN. 

